The top loading of tire presses has been developed as a superior manner of introducing uncured tires into a tire press for subsequent shaping and curing. In such process the top bead of the uncured tire is initially brought into close proximity with the top mold bead ring of the press, and, after the loader clears the press, the top mold is brought downwardly until the bottom bead of the uncured tire is in close proximity to the bottom mold bead ring. During this initial transfer of the uncured tire to the top mold bead ring and the lowering of the uncured tire, the tire is held by a chuck in the top mold section. When the tire is in proper position the tire may be air inflated to snap the beads on the mold bead rings. As the press further closes the chuck is retracted into the top mold section and the shaping bladder of the center mechanism is inserted into the tire.
As an illustration of tire presses utilizing such process reference may be had to U.S. Pat. Nos. 4,447,385; 4,444,715; and 4,608,219.
The process and apparatus shown in such patents create some problems. One is the cost and complexity of the chuck within the top mold section, as well as its inability to accommodate tires having different bead diameters with minimal adjustments. If the tooling of the press is changed, the entire chuck may require replacement. Other problems are the strength and compactness of the chuck as well as the ability to use the chuck with any type center or shaping bladder mechanism. Also, with the various actuators on top of the press, the overall height of the press may become excessive and difficult to service.
Further, it has been found that air inflation for centering and seating the beads of the uncured tire on the bead rings of the press may actually cause the tire to move off center if the air pressure inlet is itself not centered with respect to the tire, or if it is too small or too close to the tire envelope.